Merge pull request #7 from bhollis/master

Make livereload work
Fix nonlocaljump error in build. Though that was in the last commit.
Incorrectly recreated previous patch
Version bump [no-ci]
correct version for 3.0
update gem homepage. fixes #11
Use MM core logger, don't reload until sitemap is finished.
Add example of snippet to add to the Gemfile
Merge pull request #16 from demersdesigns/master

Add snippet showing what needs to be added to Gemfile to get live reload up and running.
Document the extension options
implement grace_period

sleep for as many seconds before actually reacting to file change
notifications.
document grace period option
Merge pull request #18 from artm/grace_period

implement grace_period
keep reactor thread across preview server reloads
Merge pull request #21 from artm/dont_leak_reactor

keep reactor thread across preview server reloads
ignore ignored files
Merge pull request #22 from ouvrages/ignore_ignored_files

ignore ignored files
Add a version of middleman-livereload for the new 3.1 extension mechanism. Incidentally fixes #15